Tailoring ohmic contact of CdZnTe based device using a ZnTe:Cu film interlayer

Abstract

ZnTe materials exhibit distinctive characteristics that render them exceptionally suitable for the utilization in circumventing the electrode contact issue for the CdZnTe based devices for photoelectric applications. This work employed the co-sputtering technique to fabricate ZnTe:Cu films, probing the influences of Copper (Cu) sputtering power on the film's structural, morphological, optical, and electrical properties. It is disclosed that the sputtering power of the Cu target leads to a proportional increase in CuxTe compounds within the ZnTe:Cu films. Notably, an increase in the sputtering power of the Cu target is found to enhance the carrier concentration of the film, but not decrease the resistivity. This unnormal arose is due to a substantial reduction in carrier mobility at higher Cu target sputtering powers. The ZnTe:Cu film exhibits relatively lower resistivity when the sputtering power of the Cu target is approximately 3 W. The optimized ZnTe:Cu film as a buffer layer for the electrode is favor of remarkable improving the ohmic contact properties between the electrode and the CdZnTe, exhibiting a low contact resistivity of 0.62 Ω cm2. This work offers a promising approach to ameliorate the contact performance for the CdZnTe devices with high performance and high reliability.